Nick Upton / Radio-collared Edible / Fat Dormouse (Glis glis) being taken from its winter hibernation burrow during a survey in woodland where this European species has become naturalised, Buckinghamshire, UK, Apr...

Nick Upton / Sleepy, radio-collared Edible / Fat Dormouse (Glis glis) excavated from its winter hibernation burrow held during a survey in woodland where this European species has become naturalised, Buckinghamshi...

Nick Upton / Radio-collared Edible / Fat Dormouse (Glis glis) in its winter hibernation burrow, excavated during a survey in woodland where this European species has become naturalised, Buckinghamshire, UK, April.

Nick Upton / Roger Trout and Jia Ming Lim excavating the hibernation burrow of an Edible / Fat Dormouse (Glis glis) in woodland where this European species has become naturalised, Buckinghamshire, UK, April, Mode...

Nick Upton / Sleepy Edible / Fat Dormouse (Glis glis) excavated from its winter hibernation burrow being weighed during a survey in woodland where this European species has become naturalised, Buckinghamshire, UK,...

Nick Upton / Roger Trout and Jia Ming Lim fitting an exit tube to the hibernation burrow of an Edible / Fat Dormouse (Glis glis) after replacing it during a survey in woodland where this European species has beco...

Nick Upton / Exit tube fitted to the hibernation burrow of an Edible / Fat Dormouse (Glis glis) after replacing it during a survey in woodland where this European species has become naturalised, Buckinghamshire,...

Nick Upton / Emily Howard-Williams with Labrador Tui, who has been trained to sniff out feeding stations visited by Harvest mice (Micromys minutus), Moulton, Northampton, UK, June. Model released.

Nick Upton / Two Harvest mice (Micromys minutus) from a captive colony selected for release at a field site, Moulton College, Northampton, UK, June.

Nick Upton / Emily Howard-Williams with Labrador Tui, sitting down by a grain feeding bottle collected from a field site where Harvest mice (Micromys minutus) have been released, to indicate that this bottle has b...

Nick Upton / Emily Howard-Williams rewarding Labrador Tui by offering a Kong to play with for correctly indicating that a grain feeding bottle had been visited by Harvest mice (Micromys minutus), a technique that...

Nick Upton / Emily Howard-Williams with Labrador Tui, sniffing grain feeding bottles collected from a field site where Harvest mice (Micromys minutus) have been released, to identify which ones have been visited,...